This application is for renewal of a Predoctoral Training Program in Developmental Biology, Stem Cells, and Regeneration (DSR), which is administered at the University of Southern California (USC) Keck School of Medicine, in conjunction with affiliated faculty at the Children's Hospital Los Angeles. This training program leverages recent and dramatic growth in stem cell biology and regenerative medicine at USC, which is reflected in the creation of a new Department of Stem Cell Biology and Regenerative Medicine and a university-wide USC Stem Cell initiative that is investing large sums of money to recruit world leaders and promising junior faculty. Particular strengths of training-related research, which benefit from interactions with closely situated institutes and one of the largest public hospitals in the country, include skeletal biology, neural and sensory systems, kidney, digestive and metabolic organs, and cancer stem cells. The rationale of this training program is that cohesive, structured training in basic developmental and stem cell biology, coupled with training-grant-specific courses and activities that provide in-depth exposure to clinical problems, will best train the future generation of scientists in the field of regenerative medicine. A major strength of this training program is that it provides added value, in the form of clinical exposure, on top of a newly created DSR PhD program. In particular, each trainee is paired with a Clinical Co-Mentor, who guides the student in learning about the diseases to which their primary research relates. During the first four years of the training program, the ten funded trainees, plus an additional four trainees funded by the Dean's office, will have published 30 first-author manuscripts, received an NIH F31 fellowship, and won a number of honors and awards. The majority of trainees first enter USC through a Program in Biomedical and Biological Sciences (PIBBS) umbrella admissions program, which has seen a steady rise in the quality of its training-grant-eligible applicant pool. At the end of their first year, students join the lab of one of our 26 training faculty, matriculate in the DSR PhD program, and take an intensive summer core course in developmental and stem cell biology, followed by journal club and research presentation courses in their second year. Following a formal call for applications and external review, select students join the T32 training program in their second and sometimes third years, at which point they take a trainee-specific Clinical Perspective of Regenerative Medicine course and engage in a number of trainee-specific activities including an annual retreat, a student-led symposium, frequent interactions with their clinical co-mentor, and monthly lunch gatherings. The cohesive structure of this training program provides an extra level of clinical fluency that the trainees would not otherwise have obtained through the DSR program alone. By leveraging the unique clinical resources within the neighboring Los Angeles area with the recent growth in basic stem cell research at USC, this training program provides a focused educational experience for those promising young scientists who wish to make a future impact in regenerative medicine.